Blink:3: error: 'TwiMaster' does not name a type
Blink.cpp: In function 'long int altimeter_update()':
Blink:15: error: 'ALTIMETER_SENSOR' was not declared in this scope
Blink:23: error: 'ALTIMETER_SENSOR' was not declared in this scope

I have a new Eagle Tree V4 Datalogger, OSD Pro, GPS and Baro Altimeter. I hooked it all up as per instructions. Everything worked except the Altimeter was kind of erratic. When I first booted it up it had a zero in its display. I read near zero altitude in feet when I took off but did not return to near zero and was several feet off even though I probably only went 25 feet high. At some point it started blinking a numerical three digit code that did not clear when I rebooted it. Then it changed to the following code: 5L2 and that has remained for several flights. I have unplugged the altimeter and plugged it in again and rebooted many times. The altimeter continues to behave erratically. I thought maybe it was due to air speed or propwash so I sheilded it in a little razor blade box. This did not help. Please tell me what could be the problem. Thanks.

Edit: humm, now it says 58L. What does this mean?

OK, I was reading the display upside down? It was 572 and 587! I assume that is some type of altitude reading from sea level. My actual altitude is more like 700 feet so I assume it must be corrected to standard barometric pressure or something.

Anyway, I decided that maybe propwash on the multirotor was causing the erratic behavior so I wrapped the sensor in foam. It is much better now, withing a couple feet takeoff and landing.

Hi u2builder.
This is not the right thread for your question, it is for HOW TO USE altimeter with 3rd parties devices.
Anyway, your question is answered very well in the manual. What are the numbers and how it works.

The altimeter will never show your current altitude, but the maximum altitude reached in last flight, even you restart the sensor it will show max altitude reached from last flight, and will start reading new max altitude only if the altitude where altimeter was restarted and current altitude of altimeter is greater that 18feet.

The altimeter altitude reading can drift depending on many factors, so it is normal that you see 587 instead of 700 you claimed. (check some posts backs where I had the same question).

hello
I'm newbie. I want to use these sensors (airspeed V3) in my application in third party mode, but I need connect more than one. Can anyone tell me if there is a possibility to change the address of SENSOR

Hi guys, are there any plans to incorporate an input on the ET Guardian stabilizer for the ET Airspeed Sensor, so that the gain can be automatically controlled relative to airspeed? That is, the gain would be reduced for higher airspeeds?

Hi All!
I notice that when measuring airspeed that a pitot tube is used with both inlet pressure and static pressure. Why both? Would not just the air pressure in a tube be all you need? If you are using both inlet pressure and static pressure are you then having to add or subtract the two pressures?

for airspeed sensor you don't need do any math as eagletree is providing speed directly. am I wrong?!
Any airspeed indicator need Static and dynamic pressure to measure fluid flow velocity.
In conventional aircraft they both are needed because pressure inside cockpit is different from outside.
in our applications, static pressure is not so critical in my opinion, because our planes are not hermetically closed. The tube can be mounted just for dynamical pressure, but the static port should not be put into airflow directly.